Next.js / Node.js Developer Needed – Webhook Ingestion + Live Dashboard

We’re looking for a skilled web/software developer based in Cairo, Egypt to complete a specific development task. This is the first task of potentially many more. We’ll use this project to evaluate your accuracy, code quality, communication, and ability to deliver on time. Applications from developers outside Cairo, Egypt will be ignored. Task: Build a small service that ingests at-least-once webhooks and displays them on a live dashboard. Required stack: Next.js, Node.js, TypeScript, Docker, Google Cloud Platform. Backend requirements: POST /webhooks * Validate an HMAC signature * Ensure idempotency based on event ID * Handle duplicate webhook deliveries safely, including concurrent duplicates * Respond with 202 Accepted * Process events asynchronously * Event flow: received → processing → done / failed * Implement retries with backoff * Simulate approximately 15% failure on the first processing attempt GET /events * Return stored events * Support filtering by status Real-time updates: * SSE or WebSocket stream for live event updates Persistence: * PostgreSQL or SQLite * Data must survive application/container restarts Frontend requirements: * Live-updating event table * Filter by status * Manual retry for failed events * Aggregate counts by status * Proper empty and loading states * Graceful error and reconnect handling * UI must honestly reflect the actual backend processing state Ops / Delivery: * Dockerfile * One-command local setup * Clear README * Run instructions * Signed curl example for testing the webhook * Brief explanation of important technical decisions Testing: Please include a couple of meaningful automated tests, especially around: * HMAC validation * Idempotency / concurrent duplicate requests * Retry and failure handling We will evaluate the submission based on: * Correctness under concurrency * Idempotency and retry implementation * API and failure handling * Real-time UI behavior * Code quality * Test quality * Docker/setup simplicity * Documentation When applying, please include: * Relevant experience * Similar projects you have worked on * Estimated delivery time * Fixed-price quote * Confirmation that you are currently based in Cairo, Egypt